The 3-Stage Concrete Grinding, Honing and Polishing Process

Concrete Grinding Honing & Polishing Process

Polished concrete has captured the imagination of architects, engineers, property owners, interior designers and general contractors for a little more than 10 years. The entire design process is a mix of technical know-how, industry experience and artistic expression that can make or break the result, depending on the skill level of the polisher and crew. A good polisher will not only complete the technical training for concrete polishing, he will educate the customer on the type of processing, the total time and the cost of completing the job successfully.

Three Stages, Multiple Steps

Polishing concrete is a progressive process that changes and refines an existing concrete surface to a desired finish. This process starts with grinding and moves to honing and polishing. Each stage requires a series of steps that use consecutively finer grit abrasives to work the concrete, enhancing its aesthetic beauty, while a densifier is applied and absorbed into the concrete, creating a chemical reaction that makes it more dense and hard.

Three Types of Densifiers

  • Sodium
  • Potassium
  • Lithium

Meanwhile, a polisher must take into account variables he can control – and variable he can’t-that can affect the success of the polishing process, especially with an existing concrete slab. If it’s known that the concrete is to be polished before it is poured, use a polishing-friendly mix design and floor flatness rating for a better end result.

Controllable Variables

  • Equipment
    • Weight, RPMs, Speed
    • Planetary movement – active or passive, direction
  • Abrasives
    • Configuration of the diamonds’ face/tread
    • Saturation of diamond grit
    • Hardness of diamond bonding
    • Time to switch abrasives
  • Densifiers
    • Type
    • Application time
  • Physical grinding, honing and polishing
    • How the concrete surface is cut
    • Clarity of the cut surface
    • Refinement of the concrete from one grit to the next

Uncontrollable Variables

  • Condition of concrete surface
    • PSI
      • Residential concrete is generally a low, 2,500 PSI, hand troweled concrete mix; does not polish as well
      • Commercial concrete is a higher 3,500 PSI, machine troweled concrete mix in the open areas; hand troweled in corners and tight areas; polishes better
    • Imperfections to remove
    • Surface flatness and levelness
    • Hand or mechanically troweled
    • Presence of coatings, glues or mastics
  • The concrete mix design
    • Types of admixtures, fibers and polymers used
    • Aggregate
    • Vibrated for air removal or not

It’s All About the Grit Sequence

Polishers are looking for a number of conditions during the grinding, honing and polishing process:

  • Clarity of reflection
  • Sheen
  • Shine
  • Depth
  • Uniformity and color of reflection

To grind, hone and polish a concrete surface to the maximum “clarity of reflection,” use a sequence of grit abrasives, moving on to the next finer grit only when the previous one has done its job. This will insure a clean, crisp look of the concrete surface at a 200-, 400- and 800-grit resin while achieving a maximum surface durability.

Different stages of processed concrete look different to the seasoned eye:

  • Grinding level – the degree to which the surface is cut
    • Cream
    • Salt & Pepper
    • Exposed Aggregate
  • The level of clarity of reflection of the cut surface
    • Honed surface stops at 200- or 400-grit resin
    • Semi-polished surface stops at 400- or 800-grit resin
    • Highly polished surface stops at 1,500- or 3,000-grit resin
  • Decorative enhancements
    • Coloring with integral, acid-stained and water- or solvent-based stains and dyes
    • Saw cut patterns
    • Engraving

Runyon Surface Prep is considered a “polisher’s paradise,” because of depth and breadth of equipment and products available, including Husqvarna, HTC, STI tooling and grinders, Ameripolish, PROSOCO, Convergent, Dayton Superior and more. If you have any questions about what to choose, pricing or how-tos, don’t hesitate to contact us.

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6 thoughts on “The 3-Stage Concrete Grinding, Honing and Polishing Process

  1. Is polishing something that requires some extra tools or materials? I’d love to polish some concrete that I just laid in my back yard but I’d probably have to rent the proper equipment. Maybe I’ll look into hiring a professional to do it for me. Thanks for sharing your tips with us!

    • Hi Sergio, where are you located? We can either suggest customers who could polish your outdoor concrete, or if you’re close enough to either of our locations, we could rent equipment to you. Thanks for reading our blog!

  2. I have been wanting to get a nice, polished concrete floor in my home. I think that they look really nice if done correctly. It is really great to learn more about the stages that they go through to make the concrete look nice. I would like to find someone that knows a lot about the different variables involved with polishing, because then I would be sure that they know how to do it properly. I would also like to look into the different grinding levels to be sure that I get the concrete looking really nice. Thanks for the great post!

  3. I have been thinking about getting a nice floor for my home. It’s good to know that there are uncontrollable factors in the process of this type of floor. It looks really beautiful. I think I will have to consider it!

  4. I am so glad that I was able to find this! I have been having the hardest time polishing my concrete. I have no idea what I am doing, and I really want to make sure it turns out looking good. so I really appreciate you giving me some great tips on how to properly polish concrete. I’ll definitely make sure I follow the tips you gave, and hopefully it will turn out looking the way I want.

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